Antigenic Characterization of Potato Virus X with Monoclonal Antibodies

Abstract

A panel of mouse monoclonal antibodies (MAbs) against potato virus X (PVX) was obtained and three of these which had high affinity to the antigen were characterized in detail. These antibodies defined two epitopes on PVX and recognized native virus, viral coat protein and denatured viral coat protein in various immunological assays. Two of the MAbs and rabbit anti-PVX polyclonal antibodies bound to the 68 amino acid N-terminal peptide of the PVX coat protein. This implies that the N terminus of the PVX coat protein is exposed at the virus surface and forms a highly immunogenic antigenic determinant. In double antibody sandwich (DAS) ELISA, MAbs and their horseradish peroxidase conjugates reacted with PVX at 10 to 20 ng/ml. Monoclonal antibodies to PVXreacted with virus in potato leaves and tubers and detected the virus in DAS ELISA in various combinations, including in combination with polyclonal antibodies.